Buggy code:
private ConcurrentHashTrieMap . Result < ConcurrentHashTrieMap . SNode < K , V > > ipickupFirst ( final ConcurrentHashTrieMap . INode parent , int level , final ConcurrentHashTrieMap . BranchNode bn ) { } private void cleanParent ( final ConcurrentHashTrieMap . INode parent , final ConcurrentHashTrieMap . INode i , final int hashCode , final int level ) { } private void clean ( final ConcurrentHashTrieMap . INode i , final int level ) { } private ConcurrentHashTrieMap . MainNode toCompressed ( final ConcurrentHashTrieMap . CNode < K , V > cn , final int level ) { } private ConcurrentHashTrieMap . MainNode toContracted ( final ConcurrentHashTrieMap . CNode < K , V > cn , final int level ) { } private ConcurrentHashTrieMap . TNode < K , V > getTombNode ( final ConcurrentHashTrieMap . BranchNode an ) { } private void notNullValue ( final V value ) { } private void notNullKey ( final K key ) { } static int hash ( final Object key ) { } static < T > T [ ] updated ( final Class < T > clazz , final T [ ] array , final int position , final T n ) { } static < T > T [ ] inserted ( final Class < T > clazz , final T [ ] array , final int position , final T n ) { } static < T > T [ ] removed ( final Class < T > clazz , final T [ ] array , final int position ) { } static ConcurrentHashTrieMap . FlagPos flagPos ( final int hc , final int level , final long bitmap , final int w ) { } static long flag ( final int hc , final int level , final int w ) { } static enum ResultType { FOUND , NOTFOUND , RESTART ; } static class Result < V > { public Result ( final ConcurrentHashTrieMap . ResultType type , final V result ) { } public final V result ; public final ConcurrentHashTrieMap . ResultType type ; } static interface MainNode { } static interface BranchNode { } static interface SNode < K , V > extends ConcurrentHashTrieMap . BranchNode { int hash ( ) { } V get ( K k ) { } ConcurrentHashTrieMap . SNode < K , V > put ( K k , V v ) { } ConcurrentHashTrieMap . SNode < K , V > removed ( K k ) { } ConcurrentHashTrieMap . TNode < K , V > tombed ( ) { } ConcurrentHashTrieMap . KeyValueNode < K , V > next ( ConcurrentHashTrieMap . KeyValueNode < K , V > current ) { } } static interface TNode < K , V > extends ConcurrentHashTrieMap . MainNode { ConcurrentHashTrieMap . SNode < K , V > untombed ( ) { } } static class INode implements ConcurrentHashTrieMap . BranchNode { public INode ( final ConcurrentHashTrieMap . MainNode n ) { } public ConcurrentHashTrieMap . MainNode getMain ( ) { } public boolean casMain ( final ConcurrentHashTrieMap . MainNode expected , final ConcurrentHashTrieMap . MainNode update ) { } private static final AtomicReferenceFieldUpdater < ConcurrentHashTrieMap . INode , ConcurrentHashTrieMap . MainNode > INODE_UPDATER = AtomicReferenceFieldUpdater . newUpdater ( ConcurrentHashTrieMap . INode . class , ConcurrentHashTrieMap . MainNode . class , "main" ) ; @ SuppressWarnings ( "unused" ) private volatile ConcurrentHashTrieMap . MainNode main ; } static class CNode < K , V > implements ConcurrentHashTrieMap . MainNode { public ConcurrentHashTrieMap . CNode < K , V > inserted ( final ConcurrentHashTrieMap . FlagPos flagPos , final ConcurrentHashTrieMap . SNode < K , V > snode ) { } public ConcurrentHashTrieMap . CNode < K , V > updated ( final int position , final ConcurrentHashTrieMap . BranchNode bn ) { } public ConcurrentHashTrieMap . CNode < K , V > removed ( final ConcurrentHashTrieMap . FlagPos flagPos ) { final ConcurrentHashTrieMap . BranchNode [ ] narr = ConcurrentHashTrieMap . removed ( ConcurrentHashTrieMap . BranchNode . class , this . array , flagPos . position ) ; <START_BUG> return new ConcurrentHashTrieMap . CNode < K , V > ( narr , ( ( this . bitmap ) - ( flagPos . flag ) ) ) ; <END_BUG> } public ConcurrentHashTrieMap . CNode < K , V > copied ( ) { } CNode ( ) { } CNode ( final ConcurrentHashTrieMap . SNode < K , V > sNode , final int width ) { } CNode ( final ConcurrentHashTrieMap . SNode < K , V > sn1 , final ConcurrentHashTrieMap . SNode < K , V > sn2 , final int level , final int width ) { } CNode ( final ConcurrentHashTrieMap . BranchNode [ ] array , final long bitmap ) { } public final ConcurrentHashTrieMap . BranchNode [ ] array ; public final long bitmap ; } static class KeyValueNode < K , V > { KeyValueNode ( final K k , final V v ) { } protected final K key ; protected final V value ; } static class SingletonSNode < K , V > extends ConcurrentHashTrieMap . KeyValueNode < K , V > implements ConcurrentHashTrieMap . SNode < K , V > { SingletonSNode ( final K k , final V v ) { } @ Override public int hash ( ) { } @ Override public ConcurrentHashTrieMap . TNode < K , V > tombed ( ) { } @ Override public V get ( final Object k ) { } @ Override public ConcurrentHashTrieMap . SNode < K , V > put ( final K k , final V v ) { } @ Override public ConcurrentHashTrieMap . SNode < K , V > removed ( final Object k ) { } @ Override public ConcurrentHashTrieMap . KeyValueNode < K , V > next ( final ConcurrentHashTrieMap . KeyValueNode < K , V > current ) { }

Fix:
return new ConcurrentHashTrieMap . CNode < K , V > ( narr , ( ( this . bitmap ) ^ ( flagPos . flag ) ) ) ;